Conventionally, there has been an electrophotographic image forming apparatus that includes a developing device including a developing roller and a blade assembly for regulating a thickness of a developer layer held on the developing roller. Further, there has been known a blade assembly that includes a blade that contacts the developing roller and a supporting member that holds the blade in an overlapping manner.
In the blade assembly, the blade and the supporting member are welded to each other at a plurality of locations along the blade in an extended dimension of the blade. Therefore, the blade is formed with a plurality of weld marks that are aligned in the extended dimension of the blade.